Chronic Collection of Cerebrospinal Fluid from Rhesus Macaques () with Cisterna Magna Ports: Update on Refinements.

More than 20 y ago, we developed an animal model for chronic and continuous collection of cerebrospinal fluid (CSF) from conscious rhesus macaques. Since our previous publication in 2003, we have successfully implanted 168 rhesus macaques using this approach. Our experience enables us to provide up-to-date information regarding the model, including refine- ments to our implant design, reductions in maintenance, and new procedures for dealing with contamination.

Decreased complexity of glucose dynamics in diabetes in rhesus monkeys.

Until recently, preclinical and clinical work on diabetes has focused on the understanding of blood glucose elevation and its detrimental metabolic sequelae. The advent of continuous glucose monitoring (CGM) technology now allows real time monitoring of blood glucose levels as a time series, and thus the exploration of glucose dynamics at short time scales. Previous work has shown decreases in the complexity of glucose dynamics, as measured by multiscale entropy (MSE) analysis, in diabetes in humans, mice, and rats.

Characterization of an investigative safety pharmacology model to assess comprehensive cardiac function and structure in chronically instrumented conscious beagle dogs.

Introduction: There has been an increasing need to conduct investigative safety pharmacology studies to complement regulatory-required studies, particularly as it applies to a comprehensive assessment of cardiovascular (CV) risk.

Methods: We describe refined methodology using a combination of telemetry and direct signal acquisition to record concomitant peripheral hemodynamics, ECG, and left ventricular (LV) structure (LV chamber size and LV wall thickness) and function, including LV pressure-volume (PV) loops to determine load independent measures of contractility (end systolic elastance, Ees, and preload recruitable stroke work, PRSW) in conscious beagle dogs. Following baseline characterization, 28days of chronic rapid ventricular pacing (RVP) was performed and cardiac function monitored: both as a way to compare measures during development of dysfunction and to characterize feasibility of a model to assess CV safety in animals with underlying cardiac dysfunction.

Odanacatib increases mineralized callus during fracture healing in a rabbit ulnar osteotomy model.

The effects of the cathepsin K inhibitor odanacatib (ODN) on fracture healing were monitored for ~6 and 15 weeks post-fracture in two separate studies using the unilateral transverse mid-ulnar osteotomy model in skeletally mature female rabbits. Rabbits were pre-treated for 3-4 weeks with vehicle (Veh), ODN (2 mg/kg, po, daily), or alendronate (ALN) (0.3 mg/kg, sc, twice-weekly) prior to osteotomy.

CNS amyloid-β, soluble APP-α and -β kinetics during BACE inhibition.

BACE, a β-secretase, is an attractive potential disease-modifying therapeutic strategy for Alzheimer's disease (AD) as it results directly in the decrease of amyloid precursor protein (APP) processing through the β-secretase pathway and a lowering of CNS amyloid-β (Aβ) levels. The interaction of the β-secretase and α-secretase pathway-mediated processing of APP in the rhesus monkey (nonhuman primate; NHP) CNS is not understood. We hypothesized that CNS inhibition of BACE would result in decreased newly generated Aβ and soluble APPβ (sAPPβ), with increased newly generated sAPPα.

Acute gamma-secretase inhibition of nonhuman primate CNS shifts amyloid precursor protein (APP) metabolism from amyloid-beta production to alternative APP fragments without amyloid-beta rebound.

The accumulation of amyloid beta (Abeta) in Alzheimer's disease is caused by an imbalance of production and clearance, which leads to increased soluble Abeta species and extracellular plaque formation in the brain. Multiple Abeta-lowering therapies are currently in development: an important goal is to characterize the molecular mechanisms of action and effects on physiological processing of Abeta, as well as other amyloid precursor protein (APP) metabolites, in models which approximate human Abeta physiology. To this end, we report the translation of the human in vivo stable-isotope-labeling kinetics (SILK) method to a rhesus monkey cisterna magna ported (CMP) nonhuman primate model, and use the model to test the mechanisms of action of a gamma-secretase inhibitor (GSI).

Hemodynamic and cardiac neurotransmitter-releasing effects in conscious dogs of attention- and wake-promoting agents: a comparison of d-amphetamine, atomoxetine, modafinil, and a novel quinazolinone H3 inverse agonist.

Conscious coronary sinus-cannulated dogs were used to assess the hemodynamic effects and local cardiac norepinephrine (NE) and histamine (HA) release of 4 mechanistically diverse agents either clinically approved or representing a potential novel mechanism for the promotion of wakefulness or attention. Dosing regimens were based on reported or concurrently determined wake-promoting activities in canine models. The central nervous system stimulant, d-amphetamine [0.

Effects of inhibition of alpha-CGRP receptors on cardiac and peripheral vascular dynamics in conscious dogs with chronic heart failure.

Whether endogenous calcitonin gene-related peptide (CGRP) plays a role in heart failure is unclear. Seven dogs were instrumented with left ventricular (LV) pressure gauges, pacers, coronary occluder and aortic, atrial, and coronary sinus catheters. Hemodynamic recordings and response to alpha-CGRP challenge were obtained for baseline in the conscious state.

Enhanced hindlimb collateralization induced by acidic fibroblast growth factor is dependent upon femoral artery extraction.

Unlabelled: Recent investigations have established the feasibility of using exogenously delivered angiogenic growth factors to increase collateral artery development in animal models of myocardial and hindlimb ischemia.

Objective: Our aim was to evaluate the ability of a stabilized form of acidic fibroblast growth factor (aFGF-S117) to stimulate collateralization and arteriogenesis in the rabbit hindlimb following the surgical induction of ischemia by femoral artery extraction. A secondary objective was to examine angiogenic and arteriogenic effects of aFGF-S117 in the absence of a peripheral blood flow deficit.

Vascular endothelial growth factor stimulates angiogenesis without improving collateral blood flow following hindlimb ischemia in rabbits.

This study was designed to test the ability of adenovirus-delivered vascular endothelial growth factor (Ad-VEGF) to stimulate angiogenesis and arteriogenesis in the rabbit hindlimb following the induction of ischemia and to evaluate the functional changes in the collateral circulation. Ten days after the surgical induction of hindlimb ischemia, either a control virus (1 x 10(9) pfu) or an adenovirus containing the gene for VEGF(165) (1 x 10(6), 1 x 10(7), 1 x 10(8), or 1 x 10(9) pfu) was administered intramuscularly into the ischemic limb. Thirty days after administration of the adenoviral vectors, skeletal muscle capillary density was assessed and angiography was performed as markers of angiogenesis and arteriogenesis, respectively.

An alternative method of chronic cerebrospinal fluid collection via the cisterna magna in conscious rhesus monkeys.

Models of chronic cerebrospinal fluid (CSF) collection previously have been established for nonhuman primates and canines; many of these methods implement stainless-steel cannulas into the lateral or 4th ventricles or catheters into the cerebral or spinal subarachnoid space. These models have proved successful and reliable but unfortunately require invasive techniques to pass through the skull or require a laminectomy to enter the spinal subarachnoid space, involve the use of expensive and highly specialized stereotaxic equipment for the precise placement of the implants, and may require exteriorized hardware which is cumbersome to maintain and unaesthetic. The model we developed for the rhesus monkey allows for direct access to CSF outflow from the cisterna magna by using a 3.

Antiarrhythmic efficacy of combined I(Ks) and beta-adrenergic receptor blockade.

Suppression of malignant ventricular arrhythmias by selective blockade of the cardiac slowly activating delayed rectifier current (I(Ks)) has been demonstrated with the benzodiazepine L-768673 [(R)-2-(2,4-trifluoromethyl-phenyl)-N-[2-oxo-5-phenyl-1-(2,2,2-trifluoro-ethyl)-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl]acetamide] in canine models of recent and healed myocardial infarction. The present study extends the initial antiarrhythmic assessment of I(Ks) blockade by demonstrating prevention of ischemic malignant arrhythmias in dogs with recent (8.0 +/- 0.

Use of three infusion pumps for postoperative administration of buprenorphine or morphine in dogs.

Results of using an implantable osmotic pump, a preset disposable infusion pump, or a reusable programmable infusion pump for postoperative administration of buprenorphine or morphine in dogs undergoing abdominal surgery are described. Ten dogs underwent abdominal surgery for implantation of vascular access ports. Dogs were given buprenorphine s.